[v6.1] INFO: task hung in flush_delayed_work (2)
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syzbot
Feb 5, 2026, 9:06:33 PM (8 days ago) Feb 5
to syzkaller...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: cd9b81672742 Linux 6.1.161
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=122027fa580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f0605c5af04d7603
dashboard link: https://syzkaller.appspot.com/bug?extid=7c4ba158abfb9fc68f1a
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/7c7d6fd2ef9f/disk-cd9b8167.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/544b7fd5d4e0/vmlinux-cd9b8167.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3454f19d3753/bzImage-cd9b8167.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7c4ba1...@syzkaller.appspotmail.com
INFO: task syz-executor:4269 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:22000 pid:4269 ppid:1 flags:0x00004006
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
schedule+0xb9/0x180 kernel/sched/core.c:6638
schedule_timeout+0xbd/0x2d0 kernel/time/timer.c:2144
do_wait_for_common kernel/sched/completion.c:85 [inline]
__wait_for_common kernel/sched/completion.c:106 [inline]
wait_for_common kernel/sched/completion.c:117 [inline]
wait_for_completion+0x2c7/0x5a0 kernel/sched/completion.c:138
__flush_work+0x952/0xae0 kernel/workqueue.c:3076
flush_work kernel/workqueue.c:3097 [inline]
flush_delayed_work+0x12d/0x180 kernel/workqueue.c:3221
gfs2_clear_rgrpd+0xd3/0x6d0 fs/gfs2/rgrp.c:731
gfs2_put_super+0x844/0x8c0 fs/gfs2/super.c:634
generic_shutdown_super+0x130/0x340 fs/super.c:501
kill_block_super+0x7c/0xe0 fs/super.c:1470
deactivate_locked_super+0x93/0xf0 fs/super.c:332
cleanup_mnt+0x42c/0x4b0 fs/namespace.c:1191
task_work_run+0x1d0/0x260 kernel/task_work.c:203
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f0c9e79c117
RSP: 002b:00007fffea4a3be8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f0c9e80471f RCX: 00007f0c9e79c117
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fffea4a3ca0
RBP: 00007fffea4a3ca0 R08: 00007fffea4a4ca0 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffea4a4d30
R13: 00007f0c9e80471f R14: 0000000000195000 R15: 00007fffea4a4d70
</TASK>
INFO: task kworker/1:2H:15808 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:2H state:D stack:26960 pid:15808 ppid:2 flags:0x00004000
Workqueue: glock_workqueue glock_work_func
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
schedule+0xb9/0x180 kernel/sched/core.c:6638
io_schedule+0x7c/0xd0 kernel/sched/core.c:8798
bit_wait_io+0xd/0xc0 kernel/sched/wait_bit.c:209
__wait_on_bit_lock+0xd8/0x580 kernel/sched/wait_bit.c:90
out_of_line_wait_on_bit_lock+0x138/0x190 kernel/sched/wait_bit.c:117
wait_on_bit_lock_io include/linux/wait_bit.h:208 [inline]
__lock_buffer fs/buffer.c:69 [inline]
lock_buffer include/linux/buffer_head.h:397 [inline]
discard_buffer fs/buffer.c:1458 [inline]
block_invalidate_folio+0x37b/0x9e0 fs/buffer.c:1515
folio_invalidate mm/truncate.c:158 [inline]
truncate_cleanup_folio+0x218/0x5e0 mm/truncate.c:178
truncate_inode_pages_range+0x293/0x1090 mm/truncate.c:393
do_xmote+0x50a/0x13c0 fs/gfs2/glock.c:801
glock_work_func+0x25e/0x470 fs/gfs2/glock.c:1089
process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8cb2dfb0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8cb2e7d0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/27:
#0: ffffffff8cb2d620 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8cb2d620 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8cb2d620 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
2 locks held by getty/4028:
#0: ffff88814d687098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x429/0x1390 drivers/tty/n_tty.c:2198
1 lock held by syz-executor/4269:
#0: ffff88805f8520e0 (&type->s_umount_key#128){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362
6 locks held by kworker/1:5/4327:
#0: ffff888143695138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc9000450fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#2: ffff888027c49190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:840 [inline]
#2: ffff888027c49190 (&dev->mutex){....}-{3:3}, at: hub_event+0x19f/0x5560 drivers/usb/core/hub.c:5845
#3: ffff888027c4c4f8 (&port_dev->status_lock){+.+.}-{3:3}, at: usb_lock_port drivers/usb/core/hub.c:3200 [inline]
#3: ffff888027c4c4f8 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5413 [inline]
#3: ffff888027c4c4f8 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5657 [inline]
#3: ffff888027c4c4f8 (&port_dev->status_lock){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5817 [inline]
#3: ffff888027c4c4f8 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_event+0x30d9/0x5560 drivers/usb/core/hub.c:5899
#4: ffff88802719e968 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5414 [inline]
#4: ffff88802719e968 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5657 [inline]
#4: ffff88802719e968 (hcd->address0_mutex){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5817 [inline]
#4: ffff88802719e968 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_event+0x3110/0x5560 drivers/usb/core/hub.c:5899
#5: ffffffff8d67cab0 (ehci_cf_port_reset_rwsem){.+.+}-{3:3}, at: hub_port_reset+0x14f/0x1930 drivers/usb/core/hub.c:3057
2 locks held by kworker/1:2H/15808:
#0: ffff88801a3d1138 ((wq_completion)glock_workqueue){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc900050c7d00 ((work_completion)(&(&gl->gl_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
2 locks held by syz.3.2797/18740:
#0: ffff888072a38e10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
#0: ffff888072a38e10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:653 [inline]
#0: ffff888072a38e10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1399
#1: ffffffff8cb332f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
#1: ffffffff8cb332f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2ec/0x890 kernel/rcu/tree_exp.h:962
2 locks held by rm/18777:
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
<TASK>
dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3e6/0x460 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xeee/0xf30 kernel/hung_task.c:377
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 18779 Comm: dhcpcd-run-hook Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:check_preemption_disabled+0x42/0x110 lib/smp_processor_id.c:55
Code: 65 8b 05 21 b0 d5 75 65 8b 0d c2 05 d6 75 f7 c1 ff ff ff 7f 74 1f 65 48 8b 0c 25 28 00 00 00 48 3b 4c 24 08 0f 85 c4 00 00 00 <48> 83 c4 10 5b 41 5e 41 5f 5d c3 48 c7 04 24 00 00 00 00 9c 8f 04
RSP: 0000:ffffc9000c33f8a8 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 5969dcd732bf7000
RDX: 0000000000000000 RSI: ffffffff8a8c1f00 RDI: ffffffff8adf0c20
RBP: ffffc9000c33f9e8 R08: ffffffff8e1fc32f R09: 1ffffffff1c3f865
R10: dffffc0000000000 R11: fffffbfff1c3f866 R12: 0000000000000000
R13: 1ffff92001867f28 R14: 0000000000000246 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe1776b7940 CR3: 00000000477f1000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
lockdep_recursion_inc kernel/locking/lockdep.c:462 [inline]
lock_acquire+0x181/0x4a0 kernel/locking/lockdep.c:5661
rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
rcu_read_lock_sched include/linux/rcupdate.h:883 [inline]
pfn_valid+0xe9/0x420 include/linux/mmzone.h:1857
page_table_check_set+0x25/0x6d0 mm/page_table_check.c:108
page_table_check_pte_set include/linux/page_table_check.h:83 [inline]
set_pte_at arch/x86/include/asm/pgtable.h:1009 [inline]
do_set_pte+0x452/0x460 mm/memory.c:4424
filemap_map_pages+0xc8b/0x11c0 mm/filemap.c:3513
do_fault_around mm/memory.c:4598 [inline]
do_read_fault mm/memory.c:4624 [inline]
do_fault mm/memory.c:4758 [inline]
handle_pte_fault mm/memory.c:5029 [inline]
__handle_mm_fault mm/memory.c:5171 [inline]
handle_mm_fault+0x2991/0x3ee0 mm/memory.c:5292
do_user_addr_fault+0x51f/0xb10 arch/x86/mm/fault.c:1340
handle_page_fault arch/x86/mm/fault.c:1431 [inline]
exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1487
asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0033:0x7fe177792289
Code: ff 49 8b 45 10 48 8b a5 b8 fe ff ff 48 85 c0 0f 84 0b 09 00 00 49 8b 75 00 48 8d 14 30 49 89 55 10 48 85 d2 0f 84 f6 08 00 00 <48> 8b 02 49 8d 4d 40 bf ff ff ff 6f 41 ba 29 00 00 70 48 85 c0 75
RSP: 002b:00007ffdafc01390 EFLAGS: 00010202
RAX: 00000000001d0940 RBX: 0000000000000004 RCX: 00007fe1777ad242
RDX: 00007fe1776b7940 RSI: 00007fe1774e7000 RDI: 00007fe1776ba000
RBP: 00007ffdafc01800 R08: 00000000ffffffff R09: 0000000000000000
R10: 0000000000000032 R11: 00007ffdafc01390 R12: 00007ffdafc01160
R13: 00007fe1777895f0 R14: 00007ffdafc018a0 R15: 00007fe1776ba000
</TASK>
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
syzbot found the following issue on:
HEAD commit: cd9b81672742 Linux 6.1.161
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=122027fa580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f0605c5af04d7603
dashboard link: https://syzkaller.appspot.com/bug?extid=7c4ba158abfb9fc68f1a
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/7c7d6fd2ef9f/disk-cd9b8167.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/544b7fd5d4e0/vmlinux-cd9b8167.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3454f19d3753/bzImage-cd9b8167.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7c4ba1...@syzkaller.appspotmail.com
INFO: task syz-executor:4269 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:22000 pid:4269 ppid:1 flags:0x00004006
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
schedule+0xb9/0x180 kernel/sched/core.c:6638
schedule_timeout+0xbd/0x2d0 kernel/time/timer.c:2144
do_wait_for_common kernel/sched/completion.c:85 [inline]
__wait_for_common kernel/sched/completion.c:106 [inline]
wait_for_common kernel/sched/completion.c:117 [inline]
wait_for_completion+0x2c7/0x5a0 kernel/sched/completion.c:138
__flush_work+0x952/0xae0 kernel/workqueue.c:3076
flush_work kernel/workqueue.c:3097 [inline]
flush_delayed_work+0x12d/0x180 kernel/workqueue.c:3221
gfs2_clear_rgrpd+0xd3/0x6d0 fs/gfs2/rgrp.c:731
gfs2_put_super+0x844/0x8c0 fs/gfs2/super.c:634
generic_shutdown_super+0x130/0x340 fs/super.c:501
kill_block_super+0x7c/0xe0 fs/super.c:1470
deactivate_locked_super+0x93/0xf0 fs/super.c:332
cleanup_mnt+0x42c/0x4b0 fs/namespace.c:1191
task_work_run+0x1d0/0x260 kernel/task_work.c:203
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f0c9e79c117
RSP: 002b:00007fffea4a3be8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f0c9e80471f RCX: 00007f0c9e79c117
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fffea4a3ca0
RBP: 00007fffea4a3ca0 R08: 00007fffea4a4ca0 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffea4a4d30
R13: 00007f0c9e80471f R14: 0000000000195000 R15: 00007fffea4a4d70
</TASK>
INFO: task kworker/1:2H:15808 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:2H state:D stack:26960 pid:15808 ppid:2 flags:0x00004000
Workqueue: glock_workqueue glock_work_func
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
schedule+0xb9/0x180 kernel/sched/core.c:6638
io_schedule+0x7c/0xd0 kernel/sched/core.c:8798
bit_wait_io+0xd/0xc0 kernel/sched/wait_bit.c:209
__wait_on_bit_lock+0xd8/0x580 kernel/sched/wait_bit.c:90
out_of_line_wait_on_bit_lock+0x138/0x190 kernel/sched/wait_bit.c:117
wait_on_bit_lock_io include/linux/wait_bit.h:208 [inline]
__lock_buffer fs/buffer.c:69 [inline]
lock_buffer include/linux/buffer_head.h:397 [inline]
discard_buffer fs/buffer.c:1458 [inline]
block_invalidate_folio+0x37b/0x9e0 fs/buffer.c:1515
folio_invalidate mm/truncate.c:158 [inline]
truncate_cleanup_folio+0x218/0x5e0 mm/truncate.c:178
truncate_inode_pages_range+0x293/0x1090 mm/truncate.c:393
do_xmote+0x50a/0x13c0 fs/gfs2/glock.c:801
glock_work_func+0x25e/0x470 fs/gfs2/glock.c:1089
process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8cb2dfb0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8cb2e7d0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/27:
#0: ffffffff8cb2d620 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8cb2d620 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8cb2d620 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
2 locks held by getty/4028:
#0: ffff88814d687098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x429/0x1390 drivers/tty/n_tty.c:2198
1 lock held by syz-executor/4269:
#0: ffff88805f8520e0 (&type->s_umount_key#128){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362
6 locks held by kworker/1:5/4327:
#0: ffff888143695138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc9000450fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#2: ffff888027c49190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:840 [inline]
#2: ffff888027c49190 (&dev->mutex){....}-{3:3}, at: hub_event+0x19f/0x5560 drivers/usb/core/hub.c:5845
#3: ffff888027c4c4f8 (&port_dev->status_lock){+.+.}-{3:3}, at: usb_lock_port drivers/usb/core/hub.c:3200 [inline]
#3: ffff888027c4c4f8 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5413 [inline]
#3: ffff888027c4c4f8 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5657 [inline]
#3: ffff888027c4c4f8 (&port_dev->status_lock){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5817 [inline]
#3: ffff888027c4c4f8 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_event+0x30d9/0x5560 drivers/usb/core/hub.c:5899
#4: ffff88802719e968 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5414 [inline]
#4: ffff88802719e968 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5657 [inline]
#4: ffff88802719e968 (hcd->address0_mutex){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5817 [inline]
#4: ffff88802719e968 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_event+0x3110/0x5560 drivers/usb/core/hub.c:5899
#5: ffffffff8d67cab0 (ehci_cf_port_reset_rwsem){.+.+}-{3:3}, at: hub_port_reset+0x14f/0x1930 drivers/usb/core/hub.c:3057
2 locks held by kworker/1:2H/15808:
#0: ffff88801a3d1138 ((wq_completion)glock_workqueue){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc900050c7d00 ((work_completion)(&(&gl->gl_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
2 locks held by syz.3.2797/18740:
#0: ffff888072a38e10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
#0: ffff888072a38e10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:653 [inline]
#0: ffff888072a38e10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1399
#1: ffffffff8cb332f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
#1: ffffffff8cb332f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2ec/0x890 kernel/rcu/tree_exp.h:962
2 locks held by rm/18777:
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
<TASK>
dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3e6/0x460 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xeee/0xf30 kernel/hung_task.c:377
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 18779 Comm: dhcpcd-run-hook Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:check_preemption_disabled+0x42/0x110 lib/smp_processor_id.c:55
Code: 65 8b 05 21 b0 d5 75 65 8b 0d c2 05 d6 75 f7 c1 ff ff ff 7f 74 1f 65 48 8b 0c 25 28 00 00 00 48 3b 4c 24 08 0f 85 c4 00 00 00 <48> 83 c4 10 5b 41 5e 41 5f 5d c3 48 c7 04 24 00 00 00 00 9c 8f 04
RSP: 0000:ffffc9000c33f8a8 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 5969dcd732bf7000
RDX: 0000000000000000 RSI: ffffffff8a8c1f00 RDI: ffffffff8adf0c20
RBP: ffffc9000c33f9e8 R08: ffffffff8e1fc32f R09: 1ffffffff1c3f865
R10: dffffc0000000000 R11: fffffbfff1c3f866 R12: 0000000000000000
R13: 1ffff92001867f28 R14: 0000000000000246 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe1776b7940 CR3: 00000000477f1000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
lockdep_recursion_inc kernel/locking/lockdep.c:462 [inline]
lock_acquire+0x181/0x4a0 kernel/locking/lockdep.c:5661
rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
rcu_read_lock_sched include/linux/rcupdate.h:883 [inline]
pfn_valid+0xe9/0x420 include/linux/mmzone.h:1857
page_table_check_set+0x25/0x6d0 mm/page_table_check.c:108
page_table_check_pte_set include/linux/page_table_check.h:83 [inline]
set_pte_at arch/x86/include/asm/pgtable.h:1009 [inline]
do_set_pte+0x452/0x460 mm/memory.c:4424
filemap_map_pages+0xc8b/0x11c0 mm/filemap.c:3513
do_fault_around mm/memory.c:4598 [inline]
do_read_fault mm/memory.c:4624 [inline]
do_fault mm/memory.c:4758 [inline]
handle_pte_fault mm/memory.c:5029 [inline]
__handle_mm_fault mm/memory.c:5171 [inline]
handle_mm_fault+0x2991/0x3ee0 mm/memory.c:5292
do_user_addr_fault+0x51f/0xb10 arch/x86/mm/fault.c:1340
handle_page_fault arch/x86/mm/fault.c:1431 [inline]
exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1487
asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0033:0x7fe177792289
Code: ff 49 8b 45 10 48 8b a5 b8 fe ff ff 48 85 c0 0f 84 0b 09 00 00 49 8b 75 00 48 8d 14 30 49 89 55 10 48 85 d2 0f 84 f6 08 00 00 <48> 8b 02 49 8d 4d 40 bf ff ff ff 6f 41 ba 29 00 00 70 48 85 c0 75
RSP: 002b:00007ffdafc01390 EFLAGS: 00010202
RAX: 00000000001d0940 RBX: 0000000000000004 RCX: 00007fe1777ad242
RDX: 00007fe1776b7940 RSI: 00007fe1774e7000 RDI: 00007fe1776ba000
RBP: 00007ffdafc01800 R08: 00000000ffffffff R09: 0000000000000000
R10: 0000000000000032 R11: 00007ffdafc01390 R12: 00007ffdafc01160
R13: 00007fe1777895f0 R14: 00007ffdafc018a0 R15: 00007fe1776ba000
</TASK>
---
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